Scotland Yard's famous Vice Squad, which deals with prostitution and other aspects of London's underworld, has changed its title to the rather less dynamic "Serious Crime Directorate 9: Human Exploitation and Organised Crime Command", or SCD9 for short.

The explanation is one that would draw a robust response from DCI Hunt, the old-school detective from BBC One's Life on Mars and Ashes to Ashes.

Metropolitan Police sources said the switch had been ordered in part because the word "vice" was thought to have negative "connotations".

It reflects a growing trend by law enforcement agencies to treat prostitutes as victims rather than as offenders.

Over the decades the Vice Squad have led some of Met's most celebrated cases. Its detectives had dealings with Ronnie and Reggie Kray when the gangster twins moved into running nightclubs in the 1960s.

The Profumo affair, which threatened to topple Harold Macmillan's Conservative government, also involved officers from Vice.

After Christine Keeler, the London call girl, was exposed as having had affairs with both John Profumo, the war secretary, and Yevgeny Ivanov, a Soviet attache, her friend Stephen Ward was charged by police with living off immoral earnings.

It was the Vice Squad that led the prosecution of Cynthia Payne, the "Luncheon Voucher Madam", whose south London brothel catering for older men was raided in 1978.

She was sentenced to 18 months' imprisonment, and her life inspired the 1987 feature film Personal Services, starring Julie Walters.

Alan Moss, a police historian and former Met chief superintendent, said: "The jargon of modern policing, with all the numbers and letters, is confusing for the public and probably for people in the police as well.

"I think the names of different squads should bear the name of what they do, and the crime they are trying to combat."

The Vice Squad formed part of the wider "Clubs and Vice" unit, with detectives based near Soho, the capital's traditional red light district.

Vice Squad helped officers across the city deal with brothels and streetwalkers.

It was established in 1932 as "8 Area Clubs and Vice Unit", and at one point during the Second World War it operated out of a pub in Leicester Square because its headquarters had been requisitioned by the Aliens Registration Office.

Another team now part of SCD9 is the former Obscene Publications Unit, also known as the "Dirty Squad", which targeted pornography and exploitative material.

Detective Chief Superintendent Richard Martin, head of SCD9, said the name change was necessary was because Clubs and Vice had taken on wider responsibilities for areas such as human trafficking, which meant the old title was no longer appropriate.

"We are very proud of our heritage but the team and I are very comfortable with the new name because it reflects the changing nature of what we do," he said.

"Our role is constantly evolving. While once the unit just dealt with on-street prostitution we now tackle international trafficking in highly complex covert operations."

A Scotland Yard spokeswoman said: "When it was announced Home Office funding was ending for the Human Trafficking Team the Metropolitan Police Service reviewed its response to human trafficking and immigration crime.

"This resulted in a reorganisation to ensure that we retain the capability to support victims and mount investigations against traffickers.

"The former Clubs and Vice team, which previously sat within Central Operations, moved over to the command of the Specialist Crime Directorate.

"It was renamed SCD9, the Human Exploitation and Organised Crime Command, to reflect its changed work remit."